Substituted 1-hydroxy-2,6-diaryl-4-acyloxypiperidines or 1-hydroxy-2,6-diaryl-4-acylaminopiperidines and stabilized compositions

ABSTRACT

Substituted 1-hydroxy-2,6-diaryl-4-acyloxypiperidines or 1-hydroxy-2,6-diaryl-4-acylaminopiperidines of formula I ##STR1## wherein n is 1-4, Ar 1  and Ar 2  are independently aryl or substituted aryl, R 1 , R 2 , R 3  and R 4  are independently hydrogen, alkyl, substituted alkyl, alkenyl, aryl or substituted aryl, X is --O-- or --NE--, E is hydrogen, alkyl or cycloalkyl and T is n-valent aliphatic or aromatic hydrocarbon radical, are effective in stabilizing organic materials against the deleterious effects of oxygen, heat and actinic radiation.

The present invention pertains to novel substituted1-hydroxy-2,6-diaryl-4-acyloxypiperidines or1-hydroxy-2,6-diaryl-4-acylaminopiperidines and their use as stabilizersfor various organic materials subject to the deleterious effects ofoxygen, heat or actinic radiation. The instant compounds provide bothmelt flow stabilization and good color retention during processing aswell as good retention of polymer physical properties during long-termthermooxidative stress.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,316,996 teaches that 1-hydroxy-2,6-dialkylpiperidinesare useful in preventing the discoloration of phenolic antioxidants.

1-Hydroxy-2,2,6,6-tetramethyl-4-acyloxypiperidines and other1-hydroxy-2,2,6,6-tetramethylpiperidine derivatives are known aseffective light stabilizers, but these compounds are not effective asprocessing stabilizers. They are also structurally distinct from theinstant compounds of this invention.

U.S. Pat. Nos. 4,668,721; 4,782,105; 4,876,300 and 4,898,901 describeother hydroxylamines which are useful as processing stabilizers, butthese hydroxylamines are structurally quite different from the instantcompounds.

H. Kothandraraman et al., J. Poly. Sci. Polymer Letters Ed., 23, 475(1985) report the preparation of polyacrylamides having the amino groupsubstituted by selected substituted 2,6-diarylpiperidin-4-yl moieties.The instant compounds and their utility as stabilizers are not mentionedor suggested by this scientific article.

The instant 1-hydroxy-2,6-diaryl-4-acyloxypiperidines and1-hydroxy-2,6-diaryl-4-acylaminopiperidines are novel compounds unknownin the prior art. The precursor amine starting materials are also novelcompounds.

The 1-hydroxy-2,6-diaryl-4-acyloxypiperidines and1-hydroxy-2,6-diaryl-4-acylaminopiperidines of this invention exhibitsurprisingly superior properties compared to those of the closest priorart compounds.

The instant compounds are structurally distinct from prior artcompounds. Their structures allow for the synthesis of high molecularweight compounds which have low volatility, better compatibility withthe substrate and low extractability. The instant compounds provide bothmelt flow stabilization and good resistance against discoloration duringpolymer processing. The instant compounds have superior hydrolyticstability over the state of the art phosphite stabilizers and exhibitsuperior long term heat aging and oxidative induction time over thestate of the art hydroxylamine stabilizers.

OBJECTS OF THE INVENTION

One object of this invention is to provide new substituted1-hydroxy-2,6-diaryl-4-acyloxypiperidines or new1-hydroxy-2,6-diaryl-4-acylaminopiperidines which are efficaciousstabilizers for organic materials subject to oxidative, thermal and/oractinic degradation.

Another object of the invention is to provide stabilized compositionscontaining the substituted 1-hydroxy-2,6-diaryl-4-acyloxypiperidines.

Still another object of this invention is to provide new substituted2,6-diaryl-4-acyloxypiperidines or 2,6-diaryl-4-acylaminopiperidineswhich are useful as starting materials for making the1-hydroxy-2,6-diaryl-4-acyloxypiperidine or1-hydroxy-2,6-diaryl-4-acylaminopiperidine stabilizers of thisinvention.

DETAILED DISCLOSURE

The instant invention pertains to novel substituted1-hydroxy-2,6-diaryl-4-acyloxypiperidines or1-hydroxy-2,6-diaryl-4-acylaminopiperidines of formula I ##STR2##wherein

n is 1, 2, 3 or 4;

X is --O--or --NE--,

E is hydrogen, alkyl of 1 to 20 carbon atoms or cycloalkyl of 5 to 12carbon atoms,

Ar₁ and Ar₂ are independently aryl of 6 to 10 carbon atoms; or said arylsubstituted by one to three substituents selected from the groupconsisting of alkyl of 1 to 20 carbon atoms; cycloalkyl of 5 to 12carbon atoms; phenylalkyl of 7 to 15 carbon atoms; --COOR₅ where R₅ ishydrogen or alkyl of 1 to 20 carbons; --COR₆ where R₆ is alkyl of 1 to20 carbons; --NR₇ R₈ where R₇ and R₈ are independently hydrogen or alkylof 1 to 20 carbons; --SR₉ where R₉ is aryl of 6 to 10 carbon atoms oralkyl of 1 to 20 carbon atoms; --OH; --OCH₃ ; --CN; --CF₃ ; --NO₂ ; --F;--Cl; --Br and --I;

R₁, R₂, R₃ and R₄ are independently hydrogen; a linear or branched alkylof 1 to 30 carbon atoms; or said alkyl terminated with --OR₁₀, --NR₁₁R₁₂, --SR₁₃, --COOR₁₄ or --CONR₁₅ R₁₆, where R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄are independently alkyl of 1 to 20 carbon atoms or alkenyl of 3 to 18carbon atoms, and R₁₅ and R₁₆ are independently hydrogen or the samemeaning as R₁₀ ; or said alkyl interrupted by one or more --O--, --S--,--SO--, --SO₂ --, --CO--, --COO--, --OCO--, --CONR₁₇ --, --NR₁₇ CO-- or--NR₁₈ -- where R₁₇ and R₁₈ have the same meaning as R₁₅ ; alkenyl of 3to 20 carbon atoms; aryl of 6 to 10 carbon atoms; or said arylsubstituted by one to three substituents selected from the groupconsisting of alkyl of 1 to 20 carbon atoms, cycloalkyl of 5 to 12carbon atoms, and phenylalkyl of 7 to 15 carbon atoms; and

when n is 1, T is alkyl of 1 to 20 carbon atoms or said alkylinterrupted by one or more of --O--, --S--, --SO--, --SO₂ --, --CO--,--COO--, --OCO--, --CONR₁₉ --, --NR₁₉ CO-- or --NR₂₀ -- where R₁₉ andR₂₀ have the same meaning as R₁₅ ; or aryl or substituted aryl havingthe same definition as Ar₁ ;

when n is 2, T is a direct bond; alkylene of 1 to 12 carbon atoms, orsaid alkylene interrupted by one or more of --O--, --S--, --SO--, --SO₂--, --CO--, --COO--, --OCO--, --CONR₂₁, --NR₂₁ CO-- or --NR₂₂ -- whereR₂₁ and R₂₂ have the same meaning as R₁₅ ;

when n is 3, T is alkanetriyl of 3 to 8 carbon atoms; and

when n is 4, T is alkanetetrayl of 4 to 10 carbon atoms.

All possible geometric isomers and stereoisomers which are predictableare to be included in the scope of this invention.

Preferably, n is 1 or 2.

Preferably X is --O--.

Preferably, Ar₁ and Ar₂ are the same and each is phenyl or phenylsubstituted by methyl. Most preferably Ar₁ and Ar₂ are phenyl.

Preferably, R₁, R₂, R₃ and R₄ are independently hydrogen or methyl. Mostpreferably each of R₁, R₂, R₃ and R₄ is hydrogen; or R₁ is methyl, andR₂, R₃ and R₄ are hydrogen; or R₁ and R₃ are methyl, and R₂ and R₄ arehydrogen.

Preferably, when n is 1, T is alkyl of 1 to 17 carbon atoms; mostpreferably 7 to 17 carbon atoms.

Preferably, when n is 2, T is alkylene of 2 to 10 carbon atoms; mostpreferably 2 to 8 carbon atoms.

The instant invention also pertains to stabilized compositionscontaining

(a) an organic material subject to oxidative, thermal or actinicdegradation, and

(b) an effective stabilizing amount of a compound of formula I asdefined above.

The oxidation of secondary amines to hydroxylamines usingdimethyloxirane has been reported by Murray and Singh, Synthetic Comm.1989, 19, 3509. The instant compounds are prepared by the oxidation ofthe corresponding amine with dimethyldioxirane by the procedure of Eatonand Wicks, J. Org. Chem. 1988, 53, 5353. The corresponding amine isconveniently prepared by the acylation of the corresponding4-hydroxypiperidine or 4-aminopiperidine.

These substituted 4-hydroxypiperidines, such as2,6-diphenyl-4-hydroxypiperidine,2,6-diphenyl-3-methyl-4-hydroxypiperidine and2,6-diphenyl-3,5-dimethyl-4-hydroxypiperidine, are prepared by publishedprocedures, Balasubramanian, M.; Padma, N., Tetrahedron 19, 2135 (1963).

The 2,6-diaryl-4-aminopiperidines are synthesized by oximation of thecorresponding ketone as taught by P. Geneste et al., J. Org. Chem. 41,3437 (1976) and R. Haller et al., Tetrahedron, 28, 2863 (1972); followedby reduction to the primary amine as taught by M. Uma et al., Indian J.Chem., 19B, 74 (1980).

Another aspect of the instant invention is the amine starting materialsof formula II ##STR3## used to prepare the instant compounds of formulaI. These have the same definitions as cited above for formula I exceptthat there is no hydroxyl group on the N atom in the piperidine ring inthe amine precursor starting material.

When any of Ar₁, Ar₂, R₁ to R₂₃, E or T is alkyl, such alkyl groups are,for example, methyl, ethyl, isopropyl, n-butyl, tert-butyl, tert-amyl,2-ethylhexyl, n-octyl, n-undecyl, lauryl, n-heptadecyl, n-octadecyl andeicosyl; when said radicals are cycloalkyl, they are, for example,cyclopentyl, cyclohexyl, cyclooctyl and cyclododecyl; when said radicalsare phenylalkyl, they are, for example, benzyl, phenethyl,α-methylbenzyl and α,α-dimethylbenzyl; when said radicals are aryl, theyare, for example phenyl, naphthyl, or when substituted by alkyl are, forexample, tolyl and xylyl; when said radicals are alkyl interrupted by--O--, they are for example, 3-oxaamyl and 3,6-dioxaoctyl; when T isalkyl or said alkyl interrupted by --O--, T is, for example, methylene,ethylene, trimethylene, tetramethylene, octamethylene,2,2-dimethylpropane-1,3-diyl, 3-oxapentamethylene and3,6-dioxaoctamethylene; when T is alkanetriyl, it is, for example,glyceryl, trimethylyl propane; and when T is alkanetetrayl, T is, forexample, pentaerythrityl or 1,2,3,4-butanetetrayl.

Substrates in which the instant compounds of formula I are particularlyuseful are polyolefins, such as polyethylene and polypropylene.Polypropylene is particularly well stabilized by the instant compoundsduring processing.

While the instant compounds of formula I are quite effective processstabilizers for polyolefins when used alone, compositions which alsocontain a phenolic antioxidant are also extremely well stabilized duringprocessing by this combination of process stabilizers.

In general polymers which can be stabilized include

1. Polymers of monoolefins and diolefins, for example polyethylene(which optionally can be crosslinked), polypropylene, polyisobutylene,polybutene-1, polymethylpentene-1, polyisoprene or polybutadiene, aswell as polymers of cycloolefins, for instance of cyclopentene ornorbornene.

2. Mixtures of the polymers mentioned under 1), for example mixtures ofpolypropylene with polyisobutylene.

3. Copolymers of monoolefins and diolefins with each other or with othervinyl monomers, such as, for example, ethylene/propylene,propylene/butene-1, propylene/isobutylene, ethylene/butene-1,propylene/butadiene, isobutylene/isoprene, ethylene/alkyl acrylates,ethylene/alkyl methacrylates, ethylene/vinyl acetate or ethylene/acrylicacid copolymers and their salts (ionomers) and terpolymers of ethylenewith propylene and a diene, such as hexadiene, dicyclopentadiene orethylidene-norbornene.

4. Polystyrene, poly-(p-methylstyrene).

5. Copolymers of styrene or methylstyrene with dienes or acrylicderivatives, such as, for example, styrene/butadiene,styrene/acrylonitrile, styrene/ethyl methacrylate,styrene/butadiene/ethyl acrylate, styrene/acrylonitrile/methyl acrylate;mixtures of high impact strength from styrene copolymers and anotherpolymer, such as, for example, from a polyacrylate, a diene polymer oran ethylene/propylene/diene terpolymer; and block polymers of styrene,such as, for example, styrene/butadiene/styrene,styrene/isoprene/styrene, styrene/ethylene/butylene/styrene orstyrene/ethylene/propylene/styrene.

6. Graft copolymers of styrene, such as, for example, styrene onpolybutadiene, styrene and acrylonitrile on polybutadiene, styrene andalkyl acrylates or methacrylates on polybutadiene, styrene andacrylonitrile on ethylene/propylene/diene terpolymers, styrene andacrylonitrile on polyacrylates or polymethacrylates, styrene andacrylonitrile on acrylate/butadiene copolymers, as well as mixturesthereof with the copolymers listed under 5), for instance the copolymermixtures known as ABS-, MBS-, ASA- or AES-polymers.

7. Halogen-containing polymers, such as polychloroprene, chlorinatedrubbers, chlorinated or sulfochlorinated polyethylene, epichlorohydrinhomo- and copolymers, polymers from halogen-containing vinyl compounds,as for example, polyvinylchloride, polyvinylidene chloride, polyvinylfluoride, polyvinylidene fluoride, as well as copolymers thereof, as forexample, vinyl chloride/vinylidene chloride, vinyl chloride/vinylacetate, vinylidene chloride/vinyl acetate copolymers, or vinylfluoride/vinyl ether copolymers.

8. Polymers which are derived from α,β-unsaturated acids and derivativesthereof, such as polyacrylates and polymethacrylates, polyacrylamide andpolyacrylonitrile.

9. Copolymers from the monomers mentioned under 8) with each other orwith other unsaturated monomers, such as, for instance,acrylonitrile/butadiene, acrylonitrile/alkyl acrylate,acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halogenidecopolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

10. Polymers which are derived from unsaturated alcohols and amines, oracyl derivatives thereof or acetals thereof, such as polyvinyl alcohol,polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinylmaleate, polyvinylbutyral, polyallyl phthalate or polyallyl-melamine.

11. Homopolymers and copolymers of cyclic ethers, such as polyalkyleneglycols, polyethylene oxide, polypropylene oxide or copolymers thereofwith bis-glycidyl ethers.

12. Polyacetals, such as polyoxymethylene and those polyoxymethyleneswhich contain ethylene oxide as comonomer.

13. Polyphenylene oxides and sulfides, and mixtures of polyphenyleneoxides with polystyrene.

14. Polyurethanes which are derived from polyethers, polyesters orpolybutadienes with terminal hydroxyl groups on the one side andaliphatic or aromatic polyisocyanates on the other side, as well asprecursors thereof (polyisocyanates, polyols or prepolymers).

15. Polyamides and copolyamides which are derived from diamines anddicarboxylic acids and/or from aminocarboxylic acids or thecorresponding lactams, such as polyamide 4, polyamide 6, polyamide 6/6,polyamide 6/10, polyamide 11, polyamide 12,poly-2,4,4-trimethylhexamethylene terephthalamide, poly-p-phenyleneterephthalamide or poly-m-phenylene isophthalamide, as well ascopolymers thereof with polyethers, such as for instance withpolyethylene glycol, polypropylene glycol or polytetramethylene glycols.

16. Polyureas, polyimides and polyamide-imides.

17. Polyesters which are derived from dicarboxylic acids and diolsand/or from hydroxycarboxylic acids or the corresponding lactones, suchas polyethylene terephthalate, polybutylene terephthalate,poly-1,4-dimethylol-cyclohexane terephthalate,poly-[2,2-(4-hydroxyphenyl)-propane] terephthalate andpolyhydroxybenzoates as well as block-copolyether-esters derived frompolyethers having hydroxyl end groups.

18. Polycarbonates.

19. Polysulfones, polyethersulfones and polyetherketones.

20. Crosslinked polymers which are derived from aldehydes on the onehand and phenols, ureas and melamines on the other hand, such asphenol/formaldehyde resins, urea/formaldehyde resins andmelamine/formaldehyde resins.

21. Drying and non-drying alkyd resins.

22. Unsaturated polyester resins which are derived from copolyesters ofsaturated and unsaturated dicarboxylic acids with polyhydric alcoholsand vinyl compounds as crosslinking agents, and also halogen-containingmodifications thereof of low flammability.

23. Thermosetting acrylic resins, derived from substituted acrylicesters, such as epoxy-acrylates, urethane-acrylates or polyesteracrylates.

24. Alkyd resins, polyester resins or acrylate resins in admixture withmelamine resins, urea resins, polyisocyanates or epoxide resins ascrosslinking agents.

25. Crosslinked epoxide resins which are derived from polyepoxides, forexample from bis-glycidyl ethers or from cycloaliphatic diepoxides.

26. Natural polymers, such as cellulose, rubber, gelatin and derivativesthereof which are chemically modified in a polymer homologous manner,such as cellulose acetates, cellulose propionates and cellulosebutyrates, or the cellulose ethers, such as methyl cellulose.

27. Mixtures of polymers are mentioned above, for example PP/EPDM,Polyamide 6/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS.

28. Naturally occuring and synthetic organic materials which are puremonomeric compounds or mixtures of such compounds, for example mineraloils, animal and vegetable fats, oil and waxes, or oils, fats and waxesbased on synthetic esters (e.g. phthalates, adipates, phosphates ortrimellitates) and also mixtures of synthetic esters with mineral oilsin any weight ratios, which materials may be used as plasticizers forpolymers or as textile spinning oils, as well as aqueous emulsions ofsuch materials.

29. Aqueous emulsions of natural or synthetic rubber, e.g. natural latexor latices of carboxylated styrene/butadiene copolymers.

30. Polysiloxanes such as the soft, hydrophilic polysiloxanes described,for example, in U.S. Pat. No. 4,259,467; and the hardpolyorganosiloxanes described, for example, in U.S. Pat. No. 4,355,147.

31. Polyketimines in combination with unsaturated acrylicpolyacetoacetate resins or with unsaturated acrylic resins. Theunsaturated acrylic resins include the urethane acrylates, polyetheracrylates, vinyl or acryl copolymers with pendant unsaturated groups andthe acrylated melamines. The polyketimines are prepared from polyaminesand ketones in the presence of an acid catalyst.

32. Radiation curable compositions containing ethylenically unsaturatedmonomers or oligomers and a polyunsaturated aliphatic oligomer.

33. Epoxymelamine resins such as light-stable epoxy resins crosslinkedby an epoxy functional coetherified high solids melamine resin such asLSE-4103 (Monsanto).

In general, the compounds of the present invention are employed in fromabout 0.01 to about 5% by weight of the stabilized composition, althoughthis will vary with the particular substrate and application. Anadvantageous range is from about 0.5 to about 2%, and especially 0.1 toabout 1%.

The stabilizers of the instant invention may readily be incorporatedinto the organic polymers by conventional techniques, at any convenientstage prior to the manufacture of shaped articles therefrom. Forexample, the stabilizer may be mixed with the polymer in dry powderform, or a suspension or emulsion of the stabilizer may be mixed with asolution, suspension, or emulsion of the polymer. The resultingstabilized polymer compositions of the invention may optionally alsocontain from about 0.01 to about 5%, preferably from about 0.025 toabout 2%, and especially from about 0.1 to about 1% by weight of variousconventional additives, such as the materials listed below, or mixturesthereof.

1. Antioxidants

1.1. Alkylated monophenols, for example,

2,6-di-tert-butyl-4-methylphenol

2-tert.butyl-4,6-dimethylphenol

2,6-di-tert-butyl-4-ethylphenol

2,6-di-tert-butyl-4-n-butylphenol

2,6-di-tert-butyl-4-i-butylphenol

2,6-di-cyclopentyl-4-methylphenol

2-(α-methylcyclohexyl)-4,6-dimethylphenol

2,6-di-octadecyl-4-methylphenol

2,4,6-tri-cyclohexylphenol

2,6-di-tert-butyl-4-methoxymethylphenol

1.2. Alkylated hydroquinones, for example,

2,6-di-tert-butyl-4-methoxyphenol

2,5-di-tert-butyl-hydroquinone

2,5-di-tert-amyl-hydroquinone

2,6-diphenyl-4-octadecyloxyphenol

1.3. Hydroxylated thiodiphenyl ethers, for example,

2,2'-thio-bis-(6-tert-butyl-4-methylphenol)

2,2'-thio-bis-(4-octylphenol)

4,4'-thio-bis-(6-tert-butyl-3-methylphenol)

4,4'-thio-bis-(6-tert-butyl-2-methylphenol)

1.4. Alkylidene-bisphenols, for example,

2,2'-methylene-bis-(6-tert-butyl-4-methylphenol)

2,2'-methylene-bis-(6-tert-butyl-4-ethylphenol)

2,2'-methylene-bis-[4-methyl-6-(α-methylcyclohexyl)-phenol]

2,2'-methylene-bis-(4-methyl-6-cyclohexylphenol)

2,2'-methylene-bis-(6-nonyl-4-methylphenol)

2,2'-methylene-bis-[6-(α-methylbenzyl)-4-nonylphenol]

2,2'-methylene-bis-[6-(α,α-dimethylbenzyl)-4-nonylphenol]

2,2'-methylene-bis-(4,6-di-tert-butylphenol)

2,2'-ethylidene-bis-(4,6-di-tert-butylphenol)

2,2'-ethylidene-bis-(6-tert-butyl-4-isobutylphenol)

4,4'-methylene-bis-(2,6-di-tert-butylphenol)

4,4'-methylene-bis-(6-tert-butyl-2-methylphenol)

1,1-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl-butane

2,6-di-(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol

1,1,3-tris-(5-tert-butyl-4-hydroxy-2-methylphenyl)-butane

1,1-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane

ethyleneglycol bis-[3,3-bis-(3'-tert-butyl-4'-hydroxyphenyl)-butyrate]

di-(3-tert-butyl-4-hydroxy-5-methylphenyl)-dicyclopentadiene

di-[2-(3'-tert-butyl-2'-hydroxy-5'-methyl-benzyl)-6-tert-butyl-4-methylphenyl]terephthalate.

1.5. Benzyl compounds, for example,

1,3,5-tri-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene

di-(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide

3,5-di-tert-butyl-4-hydroxybenzyl-mercapto-acetic acid isooctyl ester

bis-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithiol terephthalate

1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate

1,3,5-tris-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate

3,5-di-tert-butyl-4-hydroxybenzyl-phosphoric acid dioctadecyl ester

3,5-di-tert-butyl-4-hydroxybenzyl-phosphoric acid monoethyl ester,calcium-salt

1.6. Acylaminophenols, for example,

4-hydroxy-lauric acid anilide

4-hydroxy-stearic acid anilide

2,4-bis-octylmercapto-6-(3,5-tert-butyl-4-hydroxyanilino)-s-triazine

octyl-N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamate

1.7. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid withmonohydric or polyhydric alcohols, for example,

    ______________________________________    methanol       diethylene glycol    octadecanol    triethylene glycol    1,6-hexanediol pentaerythritol    neopentyl glycol                   tris-hydroxyethyl isocyanurate    thiodiethylene glycol                   di-hydroxyethyl oxalic acid diamide    ______________________________________

1.8. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acidwith monohydric or polyhydric alcohols, for example,

    ______________________________________    methanol       diethylene glycol    octadecanol    triethylene glycol    1,6-hexanediol pentaerythritol    neopentyl glycol                   tris-hydroxyethyl isocyanurate    thiodiethylene glycol                   di-hydroxyethyl oxalic acid diamide    ______________________________________

1.9. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid forexample,

N,N'-di-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexamethylenediamine

N,N'-di-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-trimethylenediamine

N,N'-di-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine

1.10 Diarylamines, for example,

diphenylamine, N-phenyl-1-naphthylamine,N-(4-tert-octylphenyl)-1-naphthylamine,4,4'-di-tert-octyl-diphenylamine, reaction product ofN-phenylbenzylamine and 2,4,4-trimethylpentene, reaction product ofdiphenylamine and 2,4,4-trimethylpentene, reaction product ofN-phenyl-1-naphthylamine and 2,4,4-trimethylpentene.

2. UV absorbers and light stabilizers

2.1. 2-(2'-Hydroxyphenyl)-benzotriazoles, for example, the 5'-methyl-,3',5'-di-tert-butyl-, 5'-tert-butyl-, 5'-(1,1,3,3-tetramethylbutyl)-,5-chloro-3',5'-di-tert-butyl-, 5-chloro-3'-tert-butyl-5'-methyl-,3'-sec-butyl-5'-tert-butyl-, 4'-octoxy, 3',5'-di-tert-amyl-,3',5'-bis(α,α-dimethylbenzyl),3'-tert-butyl-5'-(2-(omega-hydroxy-octa-(ethyleneoxy)carbonyl-ethyl)-,3'-dodecyl-5'-methyl-, and 3'-tert-butyl-5'-(2-octyloxycarbonyl)ethyl-,and dodecylated-5'-methyl derivatives.

2.2. 2-Hydroxy-benzophenones, for example, the 4-hydroxy-, 4-methoxy-,4-octoxy, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy, 4,2',4'-trihydroxy-and 2'-hydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of optionally substituted benzoic acids for example, phenylsalicylate, 4-tert-butylphenyl salicylate, octylphenyl salicylate,dibenzoylresorcinol, bis-(4-tert-butylbenzoyl)-resorcinol,benzoylresorcinol, 3,5-di-tert-butyl-4-hydroxybenzoic acid2,4-di-tert-butylphenyl ester and 3,5-di-tert-butyl-4-hydroxybenzoicacid hexadecyl ester.

2.4. Acrylates, for example, α-cyano-β,β-diphenylacrylic acid ethylester or isooctyl ester, α-carbomethoxy-cinnamic acid methyl ester,α-cyano-β-methyl-p-methoxy-cinnamic acid methyl ester or butyl ester,α-carbomethoxy-p-methoxy-cinnamic acid methyl ester,N-(β-carbomethoxy-β-cyanovinyl)-2-methyl-indoline.

2.5. Nickel compounds, for example, nickel complexes of2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)-phenol], such as the 1:1 or1:2 complex, optionally with additional ligands such as n-butylamine,triethanolamine or N-cyclohexyl-diethanolamine, nickeldibutyldithiocarbamate, nickel salts of4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid monoalkyl esters, suchas of the methyl, ethyl or butyl ester, nickel complexes of ketoximessuch as of 2-hydroxy-4-methyl-phenyl undecyl ketoxime, nickel complexesof 1-phenyl-4-lauroyl-5-hydroxy-pyrazole, optionally with additionalligands.

2.6. Sterically hindered amines, for example,bis-(2,2,6,6-tetramethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl) sebacate,n-butyl-3,5-di-tert.butyl-4-hydroxybenzyl malonic acidbis-(1,2,2,6,6-pentanemethylpiperidyl)ester, condensation product of1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, condensation product ofN,N'-(2,2,6,6-tetramethylpiperidyl)-hexamethylenediamine and4-tert-octylamino-2,6-dichloro-s-triazine,tris-(2,2,6,6-tetramethylpiperidyl)-nitrilotriacetate,tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate,1,1'(1,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone).

2.7. Oxalic acid diamides, for example, 4,4'-di-octyloxy-oxanilide,2,2'-di-octyloxy-5,5'-di-tert-butyl-oxanilide,2,2'-di-dodecyloxy-5,5'-di-tert-butyl-oxanilide,2-ethoxy-2'-ethyl-oxanilide, N,N'-bis (3-dimethylaminopropyl)-oxalamide,2-ethoxy-5-tert-butyl-2'-ethyloxanilide and its mixture with2-ethoxy-2'-ethyl-5,4'-di-tert-butyloxanilide and mixtures of ortho- andpara-methoxy- as well as of o- and p-ethoxy-disubstituted oxanilides.

2.8. Hydroxyphenyl-s-triazines, for example2,6-bis-(2,4-dimethylphenyl)-4-(2-hydroxy-4-octyloxyphenyl)-s-triazine;2,6-bis-(2,4-dimethylphenyl)-4-(2,4-dihydroxyphenyl)-s-triazine;2,4-bis(2,4-dihydroxyphenyl)-6-(4-chlorophenyl)-s-triazine;2,4-bis[2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(4-chlorophenyl)-s-triazine;2,4-bis[2-hydroxy-4-(2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(2,4-dimethylphenyl)-s-triazine;2,4-bis[2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(4-bromophenyl)-s-triazine;2,4-bis[2-hydroxy-4-(2-acetoxyethoxy)phenyl]-6-(4-chlorophenyl)-s-triazine,2,4-bis(2,4-dihydroxyphenyl)-6-(2,4-dimethylphenyl)-s-triazine.

3. Metal deactivators, for example, N,N'-diphenyloxalic acid diamide,N-salicylal-N'-salicyloylhydrazine, N,N'-bis-salicyloylhydrazine,N,N'-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine,3-salicyloylamino-1,2,4-triazole, bis-benzylidene-oxalic aciddihydrazide.

4. Phosphites and phosphonites, for example, triphenyl phosphite,diphenylalkyl phosphites, phenyldialkyl phosphites, tri-(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite,di-stearyl-pentaerythritol diphosphite, tris-(2,4-di-tert-butylphenyl)phosphite, di-isodecyl-pentaerythritol diphosphite,di-(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,tristearylsorbitol triphosphite, tetrakis-(2,4-di-tert-butylphenyl)4,4'-diphenylylenediphosphonite.

5. Compounds which destroy peroxide, for example, esters ofβ-thiodipropionic acid, for example the lauryl, stearyl, myristyl ortridecyl esters, mercapto-benzimidazole or the zinc salt of2-mercaptobenzimidazole, zinc dibutyl-dithiocarbamate, dioctadecyldisulfide, pentaerythritol tetrakis-(β-dodecylmercapto)-propionate. 6.Hydroxylamines, for example, N,N-dibenzylhydroxylamine,N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine,N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine,N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine,N-hexadecyl-N-octadecylhydroxylamine,N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derivedfrom hydrogenated tallow amine.

7. Nitrones, for example, N-benzyl-alpha-phenyl nitrone,N-ethyl-alpha-methyl nitrone, N-octyl-alpha-heptyl nitrone,N-lauryl-alpha-undecyl nitrone, N-tetradecyl-alpha-tridecyl nitrone,N-hexadecyl-alpha-pentadecyl nitrone,N-octadecyl-alpha-heptadecylnitrone, N-hexadecyl-alpha-heptadecylnitrone, N-octadecyl-alpha-pentadecyl nitrone,N-heptadecyl-alpha-heptadecyl nitrone, N-octadecyl-alpha-hexadecylnitrone, nitrone derived from N,N-dialkylhydroxylamine derived fromhydrogenated tallow amine.

8. Polyamide stabilizers, for example copper salts in combination withiodides and/or phosphorus compounds and salts of divalent manganese.

9. Basic co-stabilizers, for example, melamine, polyvinylpyrrolidone,dicyandiamide, triallyl cyanurate, urea derivatives, hydrazinederivatives, amines, polyamides, polyurethanes, alkali metal salts andalkaline earth metal salts of higher fatty acids for example Castearate, Zn stearate, Mg stearate, Na ricinoleate and K palmitate,antimony pyrocatecholate or zinc pyrocatecholate.

10. Nucleating agents, for example, 4-tert-butyl-benzoic acid, adipicacid, diphenylacetic acid.

11. Fillers and reinforcing agents, for example, calcium carbonate,silicates, glass fibers, asbestos, talc, kaolin, mica, barium sulfate,metal oxides and hydroxides, carbon black, graphite.

12. Other additives, for example, plasticizers, lubricants, emulsifiers,pigments, optical brighteners, flameproofing agents, anti-static agents,blowing agents and thiosynergists such as dilauryl thiodipropionate ordistearyl thiodipropionate.

The phenolic antioxidant of particular interest is selected from thegroup consisting of n-octadecyl3,5-di-tert-butyl-4-hydroxyhydrocinnamate, neopentanetetrayltetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinammate), di-n-octadecyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,thiodiethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-benzene,3,6-dioxaoctamethylenebis(3-methyl-5-tert-butyl-4-hydroxyhydrocinnamate),2,6-di-tert-butyl-p-cresol,2,2'-ethylidene-bis(4,6-di-tert-butylphenol),1,3,5-tris(2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl)isocynurate,1,1,3,-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,1,3,5-tris[2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)ethyl]isocyanurate,3,5-di-(3,5-di-tert-butyl-4-hydroxybenzyl)mesitol, hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),1-(3,5-di-tert-butyl-4-hydroxyanilino)-3,5-di(octylthio)-s-triazine,N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide),calcium bis(ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate),ethylene bis[3,3-di(3-tert-butyl-4-hydroxyphenyl)butyrate], octyl3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate,bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazide, andN,N'-bis[2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)-ethyl]-oxamide.

A most preferred phenolic antioxidant is neopentanetetrayltetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), n-octadecyl3,5-di-tert-butyl-4-hydroxyhydrocinnamate,1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,2,6-di-tert-butyl-p-cresol or2,2'-ethylidene-bis(4,6-di-tert-butylphenol).

The hindered amine compound of particular interest is selected from thegroup consisting of bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,bis(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate,di(1,2,2,6,6-pentamethylpiperidin-4-yl)(3,5-di-tert-butyl-4-hydroxybenzyl)butylmalonate,4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triaza-spiro[4.5]decane-2,4-dione,tris(2,2,6,6-tetramethylpiperidin-4-yl) nitrilotriacetate,1,2-bis(2,2,6,6-tetramethyl-3-oxopiperazin-4-yl)ethane,2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxodispiro[5.1.11.2]heneicosane, polycondensation product of2,4-dichloro-6-tert-octylamino-s-triazine and4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine),polycondensation product of1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, polycondensation product of4,4'-hexamethylenebis-(amino-2,2,6,6-tetramethylpiperidine) and1,2-dibromoethane, tetrakis(2,2,6,6-tetramethylpiperidin-4-yl)1,2,3,4-butanetetracarboxylate,tetrakis(1,2,2,6,6-pentamethylpiperidin-4-yl)1,2,3,4-butanetetracarboxylate, polycondensation product of2,4-dichloro-6-morpholino-s-triazine and4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine),N,N',N",N'"-tetrakis[(4,6-bis(butyl-2,2,6,6-tetramethyl-piperidin-4-yl)-amino-s-triazin-2-yl]-1,10-diamino-4,7-diazadecane,mixed[2,2,6,6-tetramethylpiperidin-4-yl/β,β,β',β'-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5.5]undecane)diethyl] 1,2,3,4-butanetetracarboxylate, mixed[1,2,2,6,6-pentamethylpiperidin-4-yl/β,β,β',β'-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5.5]undecane)diethyl]1,2,3,4-butanetetracarboxylate, octamethylenebis(2,2,6,6-tetramethylpiperidin-4-carboxylate) and4,4'-ethylenebis(2,2,6,6-tetramethylpiperazin-3-one).

A most preferred hindered amine compound isbis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, the polycondensationproduct of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperdine andsuccinic acid, the polycondensation product of2,4-dichloro-6-tert-octylamino-s-triazine and4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) orN,N',N",N'"-tetrakis[(4,6-bis(butyl-(2,2,6,6-tetramethyl-piperidin-4-yl)amino)-s-triazine-2-yl]-1,10-diamino-4,7-diazadecane.

The following examples are presented for the purpose of illustrationonly and are not to be construed to limit the nature or scope of theinstant invention in any manner whatsoever.

EXAMPLE 1 2,6-Diphenylpiperidin-4-yl Laurate

To a -70° C. solution of 2.50 g (9.9 mmol) of2,6-diphenyl-4-hydroxypiperidine in 80 ml of dry tetrahydrofuran (THF),4.2 mL (10.5 mmol) of n-butyllithium (2.5M in hexanes) is addeddropwise. The mixture is warmed to -20° C. and stirred for 30 minutes.The solution is then cooled again to -70° C. and a solution of 2.2 g(9.9 mmol) of lauroyl chloride in 20 mL of dry THF is then addeddropwise. The mixture is warmed to room temperature and stirred for 18hours. The mixture is added to 250 mL of brine and then extracted with2×200 mL of ether. The combined organic layers are dried over anhydrousmagnesium sulfate and concentrated under reduced pressure. The residueis purified by liquid chromatography (LC) (silica gel, ethylacetate/hexane) to give 3.2 g (74%) of the title compound as a whitesolid: mp 40°-42° C.

Analysis: Calcd for C₂₉ H₄₁ NO₂ : C, 79.9; H, 9.5; N, 3.2. Found: C,79.9; H, 9.9; N, 3.6.

EXAMPLE 2 1-Hydroxy-2,6-diphenylpiperidin-4-yl Laurate

A solution of 590 mL (27.7 mmol) of dimethyldioxirane, 0.047M in acetone(prepared by the procedure of Eaton and Wicks, J. Org. Chem. 1988, 53,5353) is added via a cannula to a 0° C. solution of 12.1 g (27.7 mmol)of 2,6-diphenyl-4-piperidyl laurate in 200 mL of acetone. After stirringfor 10 minutes at 0° C., the reaction mixture is concentrated underreduced pressure and the residue is recrystallized from methanol toyield 9.7 g (78% yield) of the title compound as a white solid: mp89°-90° C.

Analysis: Calcd for C₂₉ H₄₁ NO₂ : C, 77.1; H, 9.2; N, 3.1. Found: C,77.1; H, 9.2; N, 2.9.

EXAMPLE 3 Bis-(2,6-diphenylpiperidin-4-yl) Sebacate

The general procedure of Example 1 is repeated using 2.9 g (11.5 mmol)of 2,6-diphenyl-4-hydroxypiperidine, 4.9 mL (12.0 mmol) ofn-butyllithium (2.5M in hexanes) and 1.35 g (5.6 mmol) of sebacoylchloride. 3.5 g (93% yield) of the title compound is isolated.

EXAMPLE 4 Bis(1-hydroxy-2,6-diphenylpiperidin-4-yl) Sebacate

The general procedure of Example 2 is repeated using 2.0 g (3.0 mmol) ofbis-(2,6-diphenylpiperidin-4-yl) sebacate and 82.8 mL (6.0 mmol) ofdimethyldioxirane (0.072M in acetone). 1.6 g (76% yield) of the titlecompound is isolated after recrystallization from methanol: mp 138°-158°C.

Analysis: Calcd for C₄₄ H₅₂ N₂ O₆ : C, 75.0; H, 7.4; N, 4.0. Found: C,74.5; H, 7.4; N, 3.8.

EXAMPLE 5 2,6-Diphenyl-3-methylpiperidin-4-yl Laurate

The general procedure of Example 1 is repeated using 22.8 g (85.2 mmol)of 2,6-diphenyl-3-methyl-4-hydroxypiperidine, 34 mL (85 mmol) ofn-butyllithium (2.5M in hexanes) and 18.6 g (85.2 mmol) of lauroylchloride. 25.0 g (65% yield) of the title compound is isolated afterpurification by LC (silica gel, ethyl acetate/hexane): mp 56°-59° C.

Analysis: Calcd for C₃₀ H₄₃ NO₂ : C, 80.1; H, 9.6; N, 3.1. Found: C,80.8; H, 10.1; N, 3.0.

EXAMPLE 6 1-Hydroxy-2,6-diphenyl-3-methylpiperidin-4-yl Laurate

The general procedure of Example 2 is repeated using 11.5 g (25.5 mmol)of 2,6-diphenyl-3-methylpiperidin-4-yl laurate and 570 mL (25.5 mmol) ofdimethyldioxirane (0.045M in acetone). 11.8 g (99% yield) of the titlecompound is isolated: mp 84°-91° C.

Analysis: Calcd for C₃₀ H₄₃ NO₃ : C, 77.4; H, 9.3; N, 3.0. Found: C,77.0; H, 9.2; N, 2.8.

EXAMPLE 7 2,6-Diphenyl-3,5-dimethylpiperidin-4-yl Laurate

The general procedure of Example 1 is repeated using 28.1 g (0.10 mol)of 2,6-diphenyl-3,5-dimethyl-4-hydroxypiperidine, 40 mL (0.10 mol) ofn-butyllithium (2.5M in hexanes) and 21.8 g (0.10 mol) of lauroylchloride. 34.5 g (74% yield) of the title compound is isolated afterpurification by LC (silica gel, ethyl acetate/hexane): mp 74°-76° C.

Analysis: Calcd for C₃₁ H₄₅ NO₂ : C, 80.3; H, 9.8; N, 3.0. Found: C,80.0; H, 10.2; N, 2.6.

EXAMPLE 8 1-Hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl Laurate

The general procedure of Example 2 is repeated using 29.9 g (64.5 mmol)of 2,6-diphenyl-3,5-dimethylpiperidin-4-yl laurate and 1.24 L (64.5mmol) of dimethyldioxirane (0.050M in acetone). 30.8 g (98% yield) ofthe title compound is isolated: mp 108°-112° C.

Analysis: Calcd for C₃₁ H₄₅ NO₃ : C, 77.6; H, 9.5; N, 2.9. Found: C,77.5; H, 9.8; N, 2.5.

EXAMPLE 9 Bis-(2,6-diphenyl-3,5-dimethylpiperidin-4-yl) Sebacate

The general procedure of Example 1 is repeated using 18.0 g (64 mmol) of2,6-diphenyl-3,5-dimethyl-4-hydroxypiperidine, 25.5 mL (64 mmol) ofn-butyllithium (2.5M in hexanes) and 7.65 g (32 mmol) of sebacoylchloride. 2.7 g (12% yield) of the title compound is isolated afterpurification by LC (silica gel, ethyl acetate/hexane: mp 128°-135° C.

Analysis: Calcd for C₄₈ H₆₀ N₂ O₄ : C, 79.1; H, 8.3; N, 3.8. Found: C,78.6; H, 8.2; N, 3.7.

EXAMPLE 10 Bis-(1-hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl)Sebacate

The general procedure of Example 2 is repeated using 2.09 g (2.86 mmol)of bis-(2,6-diphenyl-3,5-dimethylpiperidin-4-yl) sebacate and 82 mL(5.72 mmol) of dimethyldioxirane (0.070M in acetone). 2.18 g (100%yield) of the title compound is isolated: mp 190°-191° C.

Analysis: Calcd for C₄₈ H₆₀ N₂ O₆ : C, 75.8; H, 8.0; N, 3.7. Found: C,75.4; H, 8.0; N, 3.6.

EXAMPLE 11 N-(2,6-Diphenyl-3,5-dimethylpiperidin-4-yl)lauramide

To a stirred 0° C. solution of 12.7 g (45.3 mmol) of2,6-diphenyl-3,5-dimethyl-4-aminopiperidine and 5.1 g (50 mmol) oftriethylamine in 150 ml of methylene chloride is added dropwise asolution of 9.9 g (45.3 mmol) of lauroyl chloride. After stirring for 30minutes at 0° C., the reaction mixture is washed with water (2×200 ml)followed by a saturated aqueous sodium bicarbonate solution (300 ml).The organic phase is separated, dried over anhydrous magnesium sulfateand then concentrated under reduced pressure. The resulting solid isrecrystallized from ethanol to give 15.4 g (73% yield) of the titlecompound as a white solid melting at 112°-114° C.

Analysis: Calcd for C₃₁ H₄₆ N₂ O: C, 80.5; H, 10.0; N, 6.0. Found: C,80.5; H, 10.4; N, 6.0.

EXAMPLE 12N-(1-Hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl)lauramide

Following the general procedure of Example 2 and using 8.56 g (18.5mmol) of N-(2,6-diphenyl-3,5-dimethylpiperidin-4-yl)lauramide, preparedin Example 11, and 462 ml of a 0.04 molar solution of dimethyldioxirane(18.5 mmol) in acetone, the title compound is isolated in a yield of7.37 g (70%) after purification by LC (silica gel; ethylacetate:hexanes) as a white solid melting at 58°-62° C.

Analysis: Calcd C₃₁ H₄₆ N₂ O₂ : C, 77.8; H, 9.7; N, 5.8. Found: C, 77.6;H, 10.2; N, 5.7.

EXAMPLE 13 Process Stabilization of Polypropylene at 525° F. (274° C.)

This example illustrates the process stabilizing effectiveness of theinstant compounds in polypropylene.

The base formulation comprises unstabilized, old technologypolypropylene (PROFAX 6501, Himont) containing 0.075% by weight ofcalcium stearate. The test additives are incorporated into thepolyproyplene by dry blending or, when the additive is a liquid, using aminimum amount of methylene chloride solvent. The solvent is thenremoved by evaporation under reduced pressure. The stabilized resinformulation is extruded at 90 rpm from a 1 inch (2.54 cm) diameterextruder at 525° F. (274° C.) with a residence time of 90 seconds.

After each of the first and fifth extrusions, the melt flow rate (ingrams/10 minutes) is determined by ASTM method D1238 on the pelletsobtained from the extruder. The results are given in the table below.

    ______________________________________              Concentration                           Melt Flow after Extrusion    Additive* (% by weight)                           1         5    ______________________________________    None      --           10.5      61.7    Compound of              0.075        4.5       7.0    Example 2    Compound of              0.075        4.3       8.8    Example 4    Compound of              0.075        4.3       8.4    Example 8    Compound of              0.075        4.2       7.6    Example 10    ______________________________________

These results show that the instant1-hydroxy-2,6-diaryl-4-acyloxypiperidines provide melt flowstabilization to polypropylene as processing stabilizers.

EXAMPLE 14 Process Stabilization of Polypropylene at 525° F. (274° C.)

This example illustrates the process stabilizing effectiveness of theinstant compounds in polypropylene in formulations containing a phenolicantioxidant.

The results using the procedure described in Example 13 on polypropyleneformulations containing an instant compound and a phenolic antioxidantare given in the table below.

    ______________________________________              Concentration                           Melt Flow after Extrusion    Additive* (% by weight)                           1         5    ______________________________________    AO A      0.075        6.7       20.2    AO A plus 0.075        3.8       6.5    Example 2 0.075    AO A plus 0.075        3.9       8.6    Example 4 0.075    AO A plus 0.075        4.3       7.4    Example 8 0.075    AO A plus 0.075        4.2       8.0    Example 10              0.075    ______________________________________     *AO A is neopentanetetrayl     tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate).

These results show that the instant1-hydroxy-2,6-diaryl-4-acyloxypiperidines in combination with a phenolicantioxidant provide melt flow stabilization to polypropylene asprocessing stabilizers.

EXAMPLE 15 Color Stabilization of Polypropylene

This example illustrates the color stabilizing effectiveness of theinstant compounds in combination with a phenolic antioxidant inpolypropylene.

Using the procedure described in Example 13, polypropylene containing aphenolic antioxidant in combination with an instant compound is extrudedinto pellets. Using the pellets obtained after each of the first andfifth extrusions as described in Example 13, the pellets are compressionmolded into 125 mil (3.2 mm) thick plaques at 193° C. Specimenyellowness index (YI) values are determinated according to ASTM methodD1925. Lower YI values indicate less discoloration. The results aregiven in the table below.

    ______________________________________            Concentration Yellowness YI after Extrusion    Additive*            (% by weight) 1           5    ______________________________________    AO A    0.075         8.05        8.60    AO A plus            0.075         6.45        7.40    Example 2            0.075    AO A plus            0.075         6.70        7.69    Example 4            0.075    AO A plus            0.075         5.45        6.34    Example 8    AO A plus            0.075         5.91        6.48    Example 10            0.075    ______________________________________     *AO A is neopentanetetrayl     tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate).

These results show that the instant1-hydroxy-2,6-diaryl-4-acyloxypiperidines in combination with a phenolicantioxidant provide color stabilization to polypropylene as processingstabilizers.

EXAMPLE 16 Long Term Heat Aging Stability of Polypropylene

Extruded pellets (of Example 14), after the first pass, are compressionmolded into 125 mil (3.2 mm) plaques at 450° F. (232° C.) and then ovenaged at 150° C. in a forced draft oven equipped with a rotatingcarousel. The time, in days, to reach a yellowness index (YI) color of50 units is deemed to represent failure. The results are given in thetable below.

    ______________________________________                Concentration    Additive*   (% by weight)                            Days to Failure    ______________________________________    AO A        0.075       43    AO A plus   0.075       50    Example 2   0.075    AO A plus   0.075       45    Example 4   0.075    AO A plus   0.075       47    Example 8   0.075    AO A plus   0.075       38    Example 10  0.075    ______________________________________     *AO A is neopentanetetrayl     tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate).

EXAMPLE 17 Long Term Heat Aging Stability of Polypropylene

Extruded pellets (of Example 14), after the first pass, are compressionmolded into 40 mil (1 mm) plaques at 450° F. (232° C.) and then ovenaged at 150° C. in a forced draft oven equipped with a rotatingcarousel. The time, in days, to physical failure is determined by a 90°bend test. The results are given in the table below.

    ______________________________________                Concentration    Additive*   (% by weight)                            Days to Failure    ______________________________________    AO A        0.075       28    AO A plus   0.075       31    Example 2   0.075    AO A plus   0.075       38    Example 4   0.075    AO A plus   0.075       38    Example 8   0.075    AO A plus   0.075       34    Example 10  0.075    ______________________________________     *AO A is neopentanetetrayl     tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate).

EXAMPLE 18 Oxidative Induction Time

Extruded pellets (of Example 14), after the first pass, are analyzed byDSC using aluminum pans/isothermal at 190° C. under oxygen according toASTM-3895-80. The time of onset and peak are is given in minutes. Theresults are given in the table below.

    ______________________________________              Concentration                           OIT Onset OIT Peak    Additive* (% by weight)                           Minutes   Minutes    ______________________________________    AO A      0.075        16        21    AO A plus 0.075        42        50    Example 2 0.075    AO A plus 0.075        31        38    Example 4 0.075    AO A plus 0.075        30        38    Example 8 0.075    AO A plus 0.075        28        37    Example 10              0.075    ______________________________________     *AO A is neopentanetetrayl     tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate).

What is claimed is:
 1. A compound which is a substituted1-hydroxy-2,6-diaryl-4-acyloxypiperidine or1-hydroxy-2,6-diaryl-4-acylaminopiperidine of formula I ##STR4## whereinn is 1,2,3 or 4;X is --O-- or --NE--, E is hydrogen, alkyl of 1 to 20carbons or cycloalkyl of 5 to 12 carbon atoms, Ar₁ and Ar₂ areindependently carbocyclic aryl of 6 to 10 carbon atoms; or said arylsubstituted by one to three substituents selected from the groupconsisting of alkyl of 1 to 20 carbon atoms; cycloalkyl of 5 to 12carbon atoms; phenylalkyl of 7 to 15 carbon atoms; --COOR₅ where R₅ ishydrogen or alkyl of 1 to 20 carbons; --COR₆ where R₆ is alkyl of 1 to20 carbons; --NR₇ R₈ where R₇ and R₈ are independently hydrogen or alkylof 1 to 20 carbons; --SR₉ where R₉ is carbocyclic aryl of 6 to 10 carbonatoms or alkyl of 1 to 20 carbon atoms; --OH; --OCH₃ ; --CN; --CF₃ ;--NO₂ ; --F; --Cl; --Br and --I; R₁, R₂, R₃ and R₄ are independentlyhydrogen; a linear or branched alkyl of 1 to 30 carbon atoms; or saidalkyl terminated with --OR₁₀, --NR₁₁ R₁₂, --SR₁₃, --COOR₁₄ or --CONR₁₅R₁₆, where R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are independently alkyl of 1 to 20carbon atoms or alkenyl of 3 to 18 carbon atoms, and R₁₅ and R₁₆ areindependently hydrogen or the same meaning as R₁₀ ; or said alkylinterrupted by one or two --O--, --S--, --SO--, --SO₂ --, --CO--,--COO--, --OCO--, --CONR₁₇ --, --NR₁₇ CO--or --NR₁₈ -- where R₁₇ and R₁₈have the same meaning as R₁₅ ; alkenyl of 3 to 20 carbon atoms;carbocyclic aryl of 6 to 10 carbon atoms; or said aryl substituted byone to three substituents selected from the group consisting of alkyl of1 to 20 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, andphenylalkyl of 7 to 15 carbon atoms; and when n is 1, T is alkyl of 1 to20 carbon atoms or said alkyl interrupted by one or two of --O--, --S--,--SO--, --SO₂ --, --CO--, --COO--, --OCO--, --CONR₁₉ --, --NR₁₉ CO--or--NR₂₀ -- where R₁₉ and R₂₀ have the same meaning as R₁₅ ; or aryl orsubstituted aryl having the same definition as Ar₁ ; when n is 2, T is adirect bond; alkylene of 1 to 12 carbon atoms, or said alkyleneinterrupted by one or two of --O--, --S--, --SO--, --SO₂ --, --CO--,--COO--, --OCO--, --CONR₂₁, --NR₂₁ CO-- or --NR₂₂ -- where R₂₁ and R₂₂have the same meaning as R₁₅ ; when n is 3, T is alkanetriyl of 3 to 8carbon atoms; and when n is 4, T is alkanetetrayl of 4 to 10 carbonatoms.
 2. A compound according to claim 1 wherein n is 1 or
 2. 3. Acompound according to claim 1 wherein Ar₁ and Ar₂ are the same and eachis phenyl or phenyl substituted by methyl.
 4. A compound according toclaim 3 wherein Ar₁ and Ar are phenyl.
 5. A compound according to claim1 wherein R₁, R₂, R₃ and R₄ are independently hydrogen or methyl.
 6. Acompound according to claim 5 wherein each of R₁, R₂, R₃ and R₄ ishydrogen; or R₁ is methyl, and R₂, R₃ and R₄ are hydrogen; or R₁ and R₃are methyl, and R₂ and R₄ are hydrogen.
 7. A compound according to claim1 wherein, when n is 1, T is alkyl of 1 to 17 carbon atoms.
 8. Acompound according to claim 7 wherein, when n is 1, T is alkyl of 7 to17 carbon atoms.
 9. A compound according to claim 1 wherein, when n is2, T is alkylene of 2 to 10 carbon atoms.
 10. A compound according toclaim 9 wherein, when n is 2, T is alkylene of 2 to 8 carbon atoms. 11.A compound according to claim 1 wherein X is --O--.
 12. The compoundaccording to claim 1 which is1-hydroxy-2,6-diphenylpiperidin-4-yllaurate; bis(1-hydroxy-2,6-diphenylpiperidin-4-yl) sebacate;1-hydroxy-2,6-diphenyl-3-methylpiperidin-4-yl laurate;1-hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl laurate;bis(1-hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl) sebacate; orN-(1-hydroxy-2,6-diphenyl-3,5-dimethylpiperidin-4-yl)lauramide.